Check if a file was made with Claude

While the title of the video has Google in it, I still found her description of how text watermarking works insightful: https://www.youtube.com/watch?v=BFksx2M93sw (Google has secretly been watermarking your text for years)

the tl;dw is that a PRNG seeded with a key the model providers control allows them to know with statistically significant probability that those sequence of words tokens came from them. The PDF, which despite being hosted on nature.com is (as of this comment) open access